1. Field
The invention relates to a telephone system for use in as a private extension telephone system, etc., and a main unit and a terminal registration method therefor. More specifically, the present invention relates to an improvement of a system in which a key telephone system and an Internet Protocol (IP) telephone terminal are combined.
2. Description of the Related Art
In recent years, as regards a telephone system, Voice over IP (VoIP) which enable voice communication over an IP network has become mainly used. This kind of system includes a login/logout function which is similar to a function applied to personal computers. Under this function, when logging in from a telephone terminal to the system, a user may use the terminal, by which the user has logged in, as a terminal specifically for his/her use. That is, the user may utilize original setting of a button function, telephone directory data, etc., without any concerns for the presence of himself/herself.
In authentication of a telephone terminal resulting from a login operation, a system referred to as media access control (MAC) address authentication has been generally used (e.g., refer to Jpn. Pat. Appln. KOKAI Publication No. 2005-117355). In this system, for performing the login operation, a password, and an extension number and an MAC address of the telephone terminal are reported to a main unit. The main unit refers to the information, and if the main unit OK'd the MAC address authentication, the main unit returns the fact to the terminal at a login origin, and completes the registration of the terminal in the system.
Meanwhile, a plurality of terminals which are located at different places request registration with the identical extension numbers in any cases. Under a service function frequently used and so called a mobile number, such requests are made often. For such a case, for example, the following (1)-(3) are possible approaches. ‘A currently registered terminal’ means a terminal which is registered at present, and ‘a new registration requesting terminal’ means a terminal which has requested later with the same number as that of the currently registered terminal.
(1) Takes preference the new registration requesting terminal and erases the registration of the currently registered terminal.
(2) Registers the new registration requesting terminal in addition to the currently registered terminal.
(3) If the currently registered terminal has been in speech when the new registration requesting terminal requested its registration, restricts the registration of the new registration requesting terminal.
The MAC address authentication are harder restricted than any of the given approaches (1)-(3), even if the user logs in with the identical extension numbers and passwords, only one terminal which has firstly requested its registration may be authenticated. To allow the registration for a plurality of terminals, a maintenance operator has to disable the MAC address authentication by a manual operation. Meanwhile, from the point of view of security, it is preferable to adopt the MAC address authentication; it has been required to cope with both security and convenience in some kind of forms. Further, it is needed to take time and effort or operation omission of an operator to release the MAC address authentication, and some sort of technical development has been expected.